Lamp socket



' E. A. EvERE'r'r LAMP SOCKET Filed oct. 2e. B325 INVENTOR.

A TTORNE Y.

, positioned EDWARD A..

Evn'nn'r'r, or NEW Yonx, N. Y.

LAMP SOCKET.

Application led October 26, 1925. Serial No. 64,855.

Ths'invention relates to' lamp bases and particularly to bases for electric lamp bulbsand 'to the 'methodof manufacturing and supporting these bases. `Heretofore certain types of bases have become established in the trade such as the screw base and thev bayonet joint base. It is found in practice however, that it is not possible to obtain an accurately source of illumination with 'bases of the established type and the present invention is directed towards obtaining thisV accuracy by a novel type of base, which` when applied to lamp bulbs enable them to be interchanged Without variation in the location of the source oi illumination. This invention is particularly applicable to incandescent lamps of the concentrated lilament type which are used to project a beam of light from a retlector'or lens and in which the ilament must be accurately positioned with relation -to the optical axis of the lens or reilector and this condition must be mainf tained as the lamp bulbs are interchanged.

Ingeneral, my invention comprises applying to the lamp bulb a special basefwhich, after cementing in place is turned down in a lathe in which the bulb has been positioned with relation to the filament so that the contour of the base bears a fixed and definite relation to the filament of the bulb without regard to any irregularities V in the contour of mercial accuracy the glass of the bulb to which the base is I cementedL-''Bulbs having bases manufacV tured in this way are absolutely alike in the.

relation of the base to the lilament andare therefore interchangeable. This result is secured without any adjustment between the base itself and the filament as the 'base -is cemented in'place. The bases cantherefore be secured to the bulbs with the usual comand without any special ad.- justments of these parts relatlve to- -each other.

These bases are also arranged so that they may be rotated in their support and posi-- tioned at any angle without 'affecting the 1 electrical connections to the filament, of the bulb. The bases are clamped in position by an outside clamping ring and maybe inserted in and removed from their support by a straight movement in the direction of the axis of the lamp bulb. Lamps can thus be'I instantly replaced with accuracy.

My lnventlon- 1s more particularly de scribed in the following specification and shown in the accompanying drawings, 1n

which) Fig. 1 is a sectional-elevation of a d lower end of this base 1s closed by a fibre washer 16 in t-he centre of which the Stud 17 E located on the vertical centre line afd.

The circuit of the filament is made through a conductor 18 which is soldered to the stud 17 and the conductor 19 which is soldered to the base 20.

They lamp bulb `is secured in a support which comprises. the insulated stand 21 of Bakelite or other suitable vmaterial which has a circular stem at 23 which is inserted in a suitably drilled aperture in the carrier 22l and to which it may be secured by the screws 32. The stand 24so thatthe engaging surfaces between 21 and 22 can be accurately machined or finished and the parts assembled with precision.

Moulded into or otherwise-'secured to the stand2l is the hollow stem 26 which, as shown in 'Fig. 1 has embedded in the insulation.

with a tapere the lamp bulb 21 is shouldered at a collar at itslowerend thread and is transversely slotted as indii` cated at 31. When the lamp base 20 is i11- serted in this tube it is clamped in place by the knurled ring 27 on the threadedstem 0f 26.

'A bar 28 extends' across the bottom of 21 and ing screw '29. The clip 30 is secured4 to this bar in line with stem 17 this forms' the circuit. established the connections'for one side of The other side 4of the circuit is projects at one side to carry the bindthrough the binding screw 33`which ex# y tends through the stand 21 to engage the 1 hollow stem 26, as indicated in Figa-3.

. It is apparent that the tubular support' 26 has a fixed and predetermin d relation to the carrier22 and that the ase20 when inserted so that collar 14 rests on the outer `edge of 26 has a fixed "and predetermined relation to the carrier 22, also that bulbs fitted with similar bases can be interchanged and maintain this condition. It willv further be observed that the bulb may be rotated in the hollow stem 26 to any extent desired without interfering with the electrical connections, that it is inserted and withdrawn by a straight up and down movement and that it may be clamped in any position by the clamping nut 27.

When a lamp of this type is to be located so that the source of illumination or filament is accurately positioned in the optical axis or focal centre of a lens or refiector, such, for instance, as is required in light signals it is necessary that the base 20 and collar 14 bear a predetermined relation to the filament 12 so that when the carrier 22 is properly positioned with reference to the lens the filament will be in the focal centre thereof. This result I secure by machining the surface of base 20 with reference to the ppsition of the filament aft-er the base has en cemented in place. i

One arrangement for carrying out this method is illustrated in Fig. 4. The lamp bulb 11 has cemented thereto in Athe usual process of manufacture the base-20 which is made from comparatively heavy stock. This base is mounted in a lathe chuck 41 and adjusted in jaws 42-43 until the filament 12 is located at the intersection of the vertical axis oL-cl and the transverse axis a-b as determined by the sighting tube 45 secured in the arm 4 4 rigidly mounted on the lathe. The sight is observed as the bulb is rot-ated in the head stock and the bulb is adjusted until the filament rotates true in the line of sight. In this position the cutting tool 47 on the carrier 46 trims down the base 20 as indicated by the dotted outline leaving the collar 14 at the bulb end and eventually cutting off the base where it enters the chuck. In this way it will be noted that it is'possible to position the collar 14 in exact relation to the filament and the contour of the base 2O is concentric With the vertical axis 0cl which is the vertical line of the filament.

.When a bulb with a base prepared in this way is assembled in the stand 21 it is apparent that the turned surface of the base will position the filament on the vertical line c-CZ and the collar 14 will position the filament horizontally on the line L -b. Thus, through the tubular support 26, stand 21 and carrier 22, the filament of any bulb is instantly positioned with relation to predetermined conditions.

It will be noted that these conditions are obtained without adjustments and by parts which rigidly engage each other. The process of changingr lamps is of the most elementary character and does not permit ofY mistake.

Having thus described my invention, I claim:

1. In a lamp bulb support, in combination, a bulb with a concentrated filament, a base on said bulb having a collar formed thereon in a predetermined relation to said filament, a hollow stem receiving said base with the collar resting upon the exposed end of said stem and clamping means for securing said base in said stem.

2. In a lamp bulb support, in combination, a bulb with a concentrated filament, a base on said bulb having a collar formed thereon in a predetermined relation to said filament, a hollow stem receiving said base with the collar resting upon the ,exposed end of said stein, said stem split longitudinally and having an egitcrior clamping nut threaded thereon for securing said base in said stem.

3. In a lamp bulb support, in combination, a bulb with a concentrated filament, a base on said bulb having a collar, formed thereon in a predetermined relation to said filament,

a hollon7 stem receiving said base with the collar resting upon the exposed end of the stem and having an annular groove formed therein, a supporting stand moulded around said groove and means for clamping said base in said stem.

et. A lamp bulb as described comprising a concentrated filament and a cylindrical one piece base, said base provided with a collar developed from said cylinder at the end adjacent said bulb, said collar having a predetermined relation to said filament.

5. In a lamp bulb support, in combination, a lamp bulb with a filament, a base on said bulb having a collar in a predetermined relation to said filament,'an insulated stem projecting from said base on the axial line of said bulb, a hollow stem receiving said base with the collar resting on one end ot said stem, a contact engaging said insulated 'stem and means exterior to said stem for` clamping said base in place.

6. The method of establishing a predetermined relation between the source of illumination of a lamp and its base comprising clamping the base in a lathe chuck, sighting the source of illumination on the centre line of the chuck and turning down the base with a lathe tool.

7 The method of establishing a predetermined relation between a concentrated filament in a lamp bulb and a base secured to the bulb with the usual commercial accuracy, comprising lclamping they base in a lathe chuck and sighting the filament throu h a sight secured to the lathe and turning own the base with a lathe tool when in this position.

8. In a lamp support of the class described, the combination of a lamp bulb having a concentrated filament and a base secured to said bulb with a fixed collar thereon adjacent the bulb having a predetermined relation to said fila-ment and a hollow stem for said base engaging said .collar whereby said filament is positioned relative to said stem.

9. In a lamp support of the class described, the combination of a lamp bulb having a concentrated filament and a base secured to said bulb having a-predetermined relation to said filament,v a carrying member, a stand inserted in an aperture in said carrying member, a hollow stem moulded in said stand with one end projecting and means embodied in said projecting end for clamping said base in said hollow stem.

10. In alamp support ofthe class described, the combination of a lamp bulb having a concentra-ted filament and la base sevsaid stand and engaging said projection so as to bring the filament into the axial line of said ho'llow stem..

Signed at New York city in the county of New York and State of New York this Mth'day of October A. D.v 1925.

f EDWARD EVERETT. 

